1. Field of the Invention
The present invention relates to a wire structure, and more particularly, to a wire structure including copper (Cu) or a copper alloy, a method for fabricating a wire, a thin film transistor (TFT) substrate, and a method for fabricating the TFT substrate.
2. Description of the Related Art
A thin film transistor (TFT) substrate is used as a substrate for a liquid crystal display (LCD) having pixels in a matrix array and an organic electro luminescence (EL) display.
An LCD, which is one of the most widely used flat panel displays, includes two substrates having a plurality of electrodes and a liquid crystal layer interposed therebetween and adjusts the amount of light transmitted therethrough by applying a voltage to the electrodes to rearrange liquid crystal molecules in the liquid crystal layer. In the LCD, thin film transistors are used as switching elements for controlling picture signals applied to the respective electrodes.
An organic electroluminescence (EL) display device displays a picture by electrically exciting phosphorescent organic material, and includes a driving TFT for supplying pixels with current necessary for light emission and a switching TFT.
As the display area of the LCD or the organic EL display device increases, the gate lines and the data lines connected to the TFTs also grow longer, causing an increase in the resistance of a wire. To solve a signal delay problem resulting from the increase in the resistance, the gate lines and the data lines should be formed of a material having as low a resistivity as possible.
In addition, for improvement of the reliability of the wire, the wire is requested to have good adhesion and to be patterned with a good profile.